1. Field of the Invention
The invention relates to a specialized wrench for removing a ring which fits tightly about a cylindrical member. More particularly the invention is concerned with such a wrench for use with a bottom loading coupler to remove the ring therefrom and to allow replacement of an annular seal used in such a coupler.
2. Prior Art
The use of bottom loading couplers to load fluid such as liquids and even fluidized powders into tank trucks and the like has been increasing steadily over the years. Such bottom loading couplers have the advantage that the transfer is completely sealed from the external atmosphere and hence noxious fumes and the like are prevented from escaping into the atmosphere and the atmosphere is prevented from contaminating the tank trucks and the like. Present Federal and State regulations require that such sealed transfer be utilized in all such loading situations by 1980.
In bottom loading couplers an annular elastomeric seal is normally abutted against a tank truck adaptor which serves as the orifice through which the tank truck is filled. Such a seal fits about a cylindrical member and is held in place by a cylindrical metal ring which fits externally thereabout and which fits tightly against the same cylindrical member. When the elastomeric annular member has worn or torn with use it has to be replaced. The prior art replacement method has consisted of utilizing a tool which resembles a screwdriver having the end thereof bent to pry up underneath the metal ring until the metal ring is loosened sufficiently to remove it by hand. Thereafter the elastomeric annular member is removed and a new elastomeric annular member inserted in its place and then the ring is replaced and forced downwardly using a mallet or the like.
Since bottom loading couplers are quite heavy this is a difficult operation often requiring two men to successfully complete it. Further, the use of a screwdriver to pry up the metallic ring has often led to damage to the metallic ring which is usually formulated of aluminum or the like. Still further the removal of the metallic ring has taken a good deal of time since this ring is usually very tightly mated about the external surface of the cylindrical member about which it fits. Yet further, the pounding in of the metallic ring with a mallet can lead to damage to the ring or to the annular elastomeric member which is being positioned thereby.
In view of the abovementioned problems of the prior art it would be advantageous to provide a wrench apparatus for removing and replacing a ring which accomplish this quickly and which accomplish this without any chance of serious damage to the ring or to the annular elastomeric member which is seated thereby. The present invention is concerned with just such an apparatus.